Electric Fish Christmas Tree

Perhaps the nerdiest of all Christmas decorations I’ve ever put up, here is the official electric fish christmas tree!

This christmas tree is not “powered” by electric fish, rather it is controlled by an electric fish. Weakly electric fish continuously produce pulses of electricity for communication and navigation in their environments– every time the fish produces a pulse, the tree lights up.

This is done with a little RadioShack magic– an Arduino board with a relay shield is all you need!

(1) Arduino Uno (or equivalent)
(2) Seed Studios Relay Shield
(3) Old extension cable (two-prong)
(4) Amplifier & Electrode (great info here on some low cost DIY options )
(5) Code below (suggestions for improvement are welcome!)

Take an old indoor extension cable, and carefully splice it and connect one of the relays. Next, a simple amplifier is connected to an electrode and dropped in the water with the electric fish. The amplifier output is connected to the analog input pin and ground of the Arduino board. Fire up your Arduino editor, and load the following code:

Posted in In the Lab
6 comments on “Electric Fish Christmas Tree
  1. aeshtaer says:

    Software pedantry: “Results stored in memory for highest speed” doesn’t really make any sense, the program doesn’t necessarily store anything in memory and regs would probably be faster than memory. The declarations of “int i” and “int randNumber” are apparently not used, and neither is “int value[5]” since “value” is re-declared locally in the loop function.

    But hey, it works. Flashy!

  2. jasongallant says:

    Thanks for the thoughts! Yes, the software is still a “draft” version just as a proof of concept– I appreciate the input though! I should also note that the software was inspired (and parts downright lifted from) the following:


  3. Rebecca says:

    This is fantastic – so clever!

  4. Shelly Richards says:

    I have no idea how I found your site…I am a mom with a high-school girl in Lincoln, NE. Your project cracked me up. Happy Electric Fishy Christmas to all of you! 😉

  5. Frankie Meier says:

    This is so fun…found you via Preuss Pets of Lansing MI

  6. Asad says:

    amazing.. Fish is controlling the Christmas Tree From the tub…

5 Pings/Trackbacks for "Electric Fish Christmas Tree"
  1. […] didn't expect to see this! A Christmas tree which is controlled by the electric fish in the lab! Electric Fish Christmas Tree | Electric Fish Lab @ MSU __________________ Check out our website Open Monday-Saturday 10-9 and Sunday 11-6 […]

  2. […] The Christmas tree device we built monitors the water for each electrical pulse produced by the fish, then turns on an electronic switch hooked up to a normal household outlet where we plugged in the lights. So the fish are actually controlling the lights: each time the fish generates an electric pulse, the lights get switched on! […]

  3. […] Find out how to make your own fish-controlled tree at Professor Jason Gallant’s blog. […]

  4. […] Find out how to make your own fish-controlled tree at Professor Jason Gallant’s blog. […]

  5. […] plataforma Arduino. La lista de los componentes necesarios y el código para programar el sistema se detallan en el blog de Gallant. Feliz navidad y felices […]

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